1-Preheat your oven: preheat your oven to 350 degrees Fahrenheit and grease a 9×13 baking pan with non-stick butter spray. This sets the stage for a smooth baking process and helps prevent sticking. In a medium bowl, mix the graham cracker crumbs, powdered sugar, and melted butter gradually until the mixture is moist but not wet and sticks together like a dream.

2-Building the Base: Once your mixture is ready, press it firmly into the bottom and sides of the pan to form a solid crust. Bake the crust for 5 to 8 minutes until the edges turn slightly golden, then let it cool for a bit. This step ensures a sturdy base that holds up to the gooey toppings you’ll add next.

3-Next: arrange the 4 chocolate bars evenly over the cooled crust and bake for about 3 minutes until the chocolate begins to melt and looks shiny. Remove it from the oven and cool for 1 to 2 minutes before spreading the mini marshmallows closely over the melted chocolate layer.

4-Baking and Finishing Touches: Set your oven to broil and place the pan inside, watching closely to broil for about 2 minutes until the marshmallows turn golden brown. Remove immediately to avoid burning that golden color is what makes them so irresistible. Let the bars cool completely, then refrigerate briefly before cutting to make slicing easier. Finally, use a sharp knife warmed under hot water and dried to cut through the sticky marshmallows cleanly, giving you neat, shareable pieces.